1. Field of the Invention
The present invention generally relates to canisters for the storage and dispensing of particulate solids, and more particularly concerns canisters of the type that are capable of dispensing a stored particulate solid in a measured amount that may be selected by the user.
2. Description of the Prior Art
There are presently available a number of canisters that may be used to store particulate solids and, in addition, are capable of dispensing a portion of the particulate solid. The array of such devices includes canisters where the user may select a volume, up to a specified maximum volume, of a particulate solid to be dispensed through a closure flap disposed proximate to the bottom of the canister, such as that described in U.S. Pat. No. 2,819,000. Further, there are presently available canisters where a single, pre-determined volume of a particulate solid may be dispensed, such as that described in U. S. Pat. No. 4,637,529, and, in addition, canisters where the user may select one of a number of pre-determined volumes of a particulate solid to be dispensed, such as that described in U.S. Pat. No. 4,782,984.
Despite the availability of such canisters, there exists a need in the art for a measuring canister that is capable of conveniently storing any of a wide variety of particulate solids, yet is capable of dispensing a measured portion of the particulate solid in a controlled manner, with the volume of material to be dispensed selected by the user to be any volume up to a maximum volume, and simultaneously preventing the remaining stored material from being dispensed or spilled during the dispensing operation.